Sight-feed lubricator system



Sept. 27, 1949. T. E. DE VlLLlERS SIGHT FEED LUBRICATOR SYSTEM FiledFeb.

7' 2712mm E72? Vii/159215 BY QZ/AI/T @177 Patented Sept. 27, 1949 SIGHT-FEED LUBRICATOR' SYSTEM Truman E. De Villiers, Okmulgee, kla., assignorto Cities Service Oil Company,u Bartlesville, Okla, a corporation ofDelaware Application February 12, 1946, Serial N 0. 646,997

9 Claims. 1

This invention relates to industrial lubrication and is particularlyconcerned with improvements in force feed lubricating systems fordelivering oil in small but metered quantities to the bearings and otherparts of engines, compressors and all heavy duty machinery.

The principal object of the invention is to provide a lubrication systemhaving a sight-feed chamber through which oil may be floated, drop bydrop under pressure, without emulsifying the fluid in the compartment tointerfere with the observation and gauging of its delivery, nor reactingwith that fluid to form gums and other heavy matter to clog deliverylines, cause valve stickage and other operating difiiculties.

It is a further and more specific object of the invention to provide asight feed fluid for pressure lubricating systems which is to allintents and purposes completely immiscible with the oil circulating inthe system, has substantially no tendency to emulsify with that oil, andto be carried out of the sight feed chamber with the delivery stream,and which remains unaffected by any of the well known addition agentsfor Detroleum lubricants, neither forming gums with them nor sufferingother chemical change.

The full nature of the invention, of the manner of obtaining theforegoing objects, and of its advantages and features, will be fullydeveloped H in the following description in the light of theaccompanying drawing, in which;

The single figure is a cross-sectional view ofa portion of a force feedlubricating system.

The sight feed chamber shown in the drawing.

is typical of the general type of device which is line It, and valves I!and IE, to a nozzle [3 mounted in the base of the chamber. The volumesodelivered may, of course, be adjusted to meet the needs of individualcases. In some instances, for example, or strokes of the pump may berequired to build up a single drop of oil on the nozzle, while in othercases the pump may deliver a drop or two during each stroke. Regardlessoi the rate of delivery, when a drop of sufficient size has been builtup, it-breaks free from the .end of nozzle l3 and floats upwardlythrough the somewhat heavier sight feed liquid 2, I I with which thechamber is filled, to join a pool of oil l5 which accumulates in the topof the chamber. It is evident, of course, that each increment of oilwhich is delivered to nozzle I3 must 'result in the displacement of anequal quantity of oil from pool l5 of the completely filled chamber,such oil being delivered under pressure through valve It to the deliveryline 11-, leading to a bearing or other point.

Inorder for the system to function properly the fluid M must begenerally immiscible with oil !5 and should have a slightly differentcolor so that the stream of droplets floating through it may be observedthrough the tubular sight glass 58 .joining base 19 with the top 20, orthrough any other conventional form of window for the a chamber, therebygiving an indication of the fact of delivery as well as a rough gauge ofthe quantity of oil flowing through delivery line H to a particularbearing point. It has been the practicein the art to fill the chamberwith glycerol or ethylene glycol, or aqueous solutions of one or both ofthese substances, and in some cases, water alone has been employed as asight feed liquid through which the oil supply is floated. While theseliquids are generally immiscible with petroleum lubricating oils, theyhave a tendency to emulsify with them, and particularly so under thehigh pressure conditions prevailing in the sight feed chamber. If thetendency is very marked, as it occasionally is, the clouding up of thesight feed liquid interferes with ready observation of the oil delivery;and in any case the emulsion tends to flow into delivery line H with theoil,

, thus resulting in a gradual loss of sight feed fluid. Since thisprocess goes on continually, even though slowly, it gives rise to thenecessity for frequent addition of fluid to the sight feed chember tomaintain it filled to the proper working level. All of these problemsbecome very much more acute when the lubricating oil in the systemcontains one or more additives, that is to say, oxidation and rustinhibitors, extreme pressure agents, and other property improvers, whichserve to promote emulsification of the sight feedfiuid. It has beenfurther noted that certain of these highly desirable addition agentsreact with glycerol and ethylene glycol to form gummy matter of a highlyviscous nature which fouls the sight feed glass so as to all but destroyits essential utility in the system, and which gradually works its'wayinto the system to clog the check valves and other delicate mechanisms.This not only makes for. increased maintenance and servicing costs'butgives rise to a very'real danger that the lubricating system will becomeso clogged as to be unable to perform its normal function withconsequent damage to the machinery which it is supposed to serve.

I have discovered that all. of the foregoing difficulties with sightfeed lubricator systems may be overcome by the use of an aqueoussolution of sugars Or other carbohydrates in the sight feed chamber. Ingeneral, any sugar seems to suffice, either in its pure state or inadmixture with other sugars. Excellent results have been obtained forexample with water solutions of cane sugar, beet sugar, and commercialsyrup made from converted starch. It has further been found that theaqueous content of the syrups may be varied within wide limits to meetthe needs of individual cases, it being necessary only that the finalproduct shall have a suitable consistency and color, and a specificgravity in excess of that of the oil in the lubricating system.

One solution which has proven highly satisfactory as a sight feed fluidconsists essentially of 25 per cent by volume of water and 75 per centby volume of a commercial mixture of corn syrup containing dextrin,maltose, dextrose and glucose, to which a small percentage of cane sugarhas been added. For convenience such a syrup will be referred to as acommercial corn syrup. This product was subjected to extensive tests inone of the sight feed chambers of a duty gas engine lubricator. In thecourse of a months operation, this substantially colorless liquidremained entirely clear, no evidence of emulsiflcation was noted, norwas it necessary to add fluid to the system during the period, and atthe end of that time the sight glass, valves and delivery lines, werefound to be entirely free of gum or other heavy viscous matter. By wayof contrast it may be noted that other sight feed chambers which werefilled with glycerine frequently required make-up fluid to maintainsatisfactory working levels and rapidly became fouled with unidentifiedgummy deposits of the kind mentioned herein before. The test wascontinued beyond the one month period, both on the mentioned gas engineand on other equipment, in competition with systerns containing bothglycerine, ethylene glycol, or a mixture of the two, and with lubricantscontaining various addition agents as well as with straight petroleumoils. After some three months testing it was quite evident that thesugar solution was far superior to the other sight feed fluids, both asto immiscibility, non-emulsification, and freedom from gumming with theoil addition agents.

I have prepared a number of other aqueous solutions of the foregoingcommercial syrup in which the sugar concentration varied between 20 and90 per cent by weight of the total, and I have also prepared both caneand beet sugar syrups having the same general range of concentration,All of these syrups have proven entirely satisfactory as sight feedfluids in lubricator systems employed for a wide variety of specialpurposes, and very much superior to the glycerol and ethylene glycolmixtures which are normally used.

It will be evident from the foregoing that my new sight feed liquidsconsist essentially of aqueous solutions of a selected sugar, or amixture of sugars, having concentrations within the limits indicatedabove. In general, however, I prefer to add a small but suflicientpercentage of a mold inhibitor to preserve them against deterioration intransit or storage. I have found, for example, that the presence ofabout 0.2 per cent by weight of methyl ester of para-hydroxybenzoic acidsuifices to inhibit molding or spoiling of my sugar solutions withoutadversely affecting any of their desirable sight feed liquid properties;and the same thing may be accomplished by the use of very smallpercentages of other well known and commercially available inhibitors ofmold growth.

Having described my invention and illustrated it by way of specificexample, what I claim as new and useful is:

1. In a force feed lubricator system, including a sight feedcompartment, and a sight feed liquid substantially filling thatcompartment, characterized in that said liquid is an aqueous solutioncontaining from 20 to per cent by weight of sugar and having a specificgravity in excess of that of oil employed in such system.

2; In a force feed lubricator system including a sight feed compartment,and a sight feed fluid substantially filling that compartment,characterized in that said fluid is an aqueous solution of from 20 to 90per cent by weight of a carbohydrate chosen from the group consisting ofsucrose, maltose, lactose, glucose, and dextrin, and in that suchsolution has a specific gravity in excess of that of the lubricating oilcirculated through such system.

3. In a force feed lubricator system including a sight feed compartment,and a sight feed fluid substantially filling that compartment,characterized in that said fluid is an aqueous solution of from 20 to 90per cent by weight of a mixture of carbohydrates chosen from the groupconsisting of sucrose, maltose, lactose, glucose, and dextrin, and inthat such solution has a specific gravity in excess of that of thelubricating oil circulated through such system.

4. In a force feed lubricator system including a sight feed compartment,and a sight feed liquid substantially filling that compartment,characterized in that said fluid consists essentially of an aqueoussolution of from 20 to 50 per cent by weight of commercial corn syruphaving a specific gravity in excess of that of oil forced through saidsight feed compartment.

5. In a force feed lubricator system including a sight feed compartment,and a sight feed liquid substantially filling that compartment,characterized in that said fluid consists essentially of an aqueoussolution of from 20 to 50 per cent by weight of commercial corn syrupand less than 1 per cent by weight of a mold inhibitor, said solutionhaving a specific gravity in excess of that of oil forced through saidsight feed compartment.

6. In a force feed lubricator system including a sight feed compartment,and a sight feed liquid substantially filling that compartment,characterized in that said fluid consists essentially of an aqueoussolution of from 20 to 50 per cent by weight of commercial corn syrupand about 0.2 per cent by weight of methyl ester of para-hydroxy-benzoicacid for inhibiting mold formation, said solution having a specificgravity in excess of that of oil forced through said sight feedcompartment.

7. In a force feed lubricator system including a sight feed compartmentand a sight feed liquid substantially filling that compartment,characterized in that said liquid consists essentially of a solution ofabout '75 per cent by weight of commercial corn syrup and about 25 percent by weight of water.

8. In a force feed lubricator system including a sight feed compartment,and a sight feed liquid 5 substantially filling that compartment,characterized in that said liquid consists essentially of a solution ofabout 75 per cent by weight of commercial corn syrup, about 25 per centby weight of water, and less than 1 per cent by weight of an inhibitorof mold formation.

9. In a force feed lubricator system including a sight feed compartment,and a sight feed liquid substantially filling that compartment,characterized in that said liquid consists essentially of a solution ofabout 75 per cent by weight of commercial corn syrup, about 25 per centby weight of water and about 0.2 per cent by weight of methyl ester ofpara-hydroxy-benzoic acid for inhibiting mold growth.

TRUMAN E. DE VILLIERS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Kniskern Dec. 26, 1933

